GAS OPERATING SYSTEM WITH EXHAUST SYSTEM

1 . A firearm, comprising:

a receiver;

a barrel mounted to the receiver and comprising a chamber located at a proximal end of the barrel and configured to receive cartridges for firing from the firearm;

a fore-end extending along the barrel;

a bolt assembly translatable along the receiver for loading cartridges into the chamber and ejecting spent casings from the firearm after firing; and

a gas operating system driving movement of the bolt assembly along the receiver, the gas operating system comprising:

a gas block having a longitudinal piston bore in fluid communication with the barrel for passage of gases generated during firing into the piston bore and comprising an opening at a distal end thereof;

a gas piston disposed within and movable along the piston bore, the gas piston operatively connected to the bolt assembly to cause the bolt assembly to be driven along the receiver for cycling the firearm; and

an exhaust tube coupled to the distal end of the gas block and defining a fluid passageway that is in communication with the piston bore to allow for release or diversion of excess gases therefrom and in a direction substantially along the fore-end; and

a regulating portion at an upstream end of the fluid passageway defined by the exhaust tube and configured to regulate or control an amount of gases entering into the fluid passageway.

2 . The firearm of claim 1 , wherein the exhaust tube comprises:

a rear portion configured to be detachably coupled to the gas block, and having an inlet of the fluid passageway defined therein the outlet at least partially in communication with the piston bore of the gas block; and

a forward portion extending forwardly from the rear portion, and through which the fluid passageway of the exhaust tube extends, wherein the fluid passageway is at least partially in fluid communication with the inlet of the rear portion, and terminates in an outlet that allows for release of gases therefrom.

3 . The firearm of claim 1 , wherein the regulating portion comprises an inlet arranged along an upstream end of the fluid passage, and wherein the inlet bore has a reduced size in relation to the fluid passage.

4 . The firearm of claim 1 , wherein the regulating portion comprises a valve assembly having a valve member that is biased toward a position at least partially obstructing an opening of the fluid passageway to restrict gas flow into the fluid passageway.

5 . The firearm of claim 1 , wherein the fluid passageway of the exhaust tube is in communication with at least one outlet channel defined along the fore-end of the firearm, the outlet channel having at least one vent opening defined along an exterior surface of the fore-end of the firearm.

6 . The firearm of claim 5 , wherein the outlet channel comprises a redirecting portion that alters a direction of the flow of gases released from the gas operating system.

7 . The firearm of claim 6 , wherein the redirecting portion comprises an angled or slanted portion.

8 . The firearm of claim 5 , wherein the opening is defined along an upper portion of the fore-end to provide a generally downwardly directed force to at least partially reduce muzzle climb experienced during firing of the firearm.

9 . The firearm of claim 1 , wherein the exhaust tube comprises a body having an exterior surface with one or more threaded portions arranged therealong and configured to matably engage with one or more threaded portions arranged along an interior surface of the gas block for connection of the gas block to the exhaust tube, wherein the exterior surface of the body further comprises an annular recess configured to at least partially receive an O-ring sufficient to substantially seal the connection between the piston bore and the exhaust tube.

10 . An auto-loading shotgun, comprising:

a receiver;

a barrel mounted to a forward end of the receiver, the barrel comprising at least one gas port arranged therealong, and a chamber located at a proximal end of the barrel and configured to receive cartridges for firing;

a magazine configured to store cartridges for loading into the chamber;

a fore-end portion having a body that at least partially surrounds the magazine and/or the barrel;

a bolt assembly translatable along the receiver for loading cartridges from the magazine into the chamber and for ejecting spent casings from the shotgun after firing; and

a gas operating system for driving movement of the bolt assembly along the receiver, the gas operating system comprising:

a gas cylinder having a longitudinal piston bore, and one or more ports in fluid communication with the piston bore and the at least one gas port of the barrel for directing passage of pressurized gases generated during firing from the barrel to the piston bore;

a gas piston disposed within and movable along the piston bore, the gas piston operatively connected to the bolt assembly such that the pressurized gases passing into the piston bore and drive the gas piston therealong so as to cause the bolt assembly to translate along the receiver for cycling the shotgun; and

at least one exhaust tube in communication with the piston bore of the gas cylinder, the at least one exhaust tube defining a fluid passageway at least partially in communication with the piston bore and at least one outlet that is in communication with one or more vents defined along an exterior surface of the body of the fore-end portion.

11 . The shotgun of claim 10 , further comprising a regulating portion located along the fluid passageway of the exhaust tube, and configured to regulate or control a flow of gases entering the fluid passageway of the exhaust tube.

12 . The shotgun of claim 11 , wherein the regulating portion comprises an inlet bore extending along the upstream end of the fluid passageway, and wherein the inlet bore has a reduced size in relation to the fluid passageway.

13 . The shotgun of claim 11 , wherein the regulating portion comprises a valve assembly having a valve member biased in a direction to at least partially obstruct an opening of the fluid passageway sufficient to restrict gas flow into the fluid passageway.

14 . The shotgun of claim 10 , wherein the exhaust tube comprises:

a rear portion configured to detachably couple to the gas block and defining a fluid passageway therethrough that communicates with the piston bore of the gas block; and

a forward portion extending forwardly from the rear portion, and through which a fluid passageway extends; and

wherein the fluid passageway extends from the rear portion through the forward portion, and terminates at the outlet to facilitate release of gases through the one or more vents.

15 . The shotgun of claim 10 , wherein the body of the fore-end portion comprises an outlet channel in communication with the at least one outlet of the fluid passageway of the exhaust tube, and wherein the outlet channel comprises a redirecting portion that alters the direction of the flow of gases passing through the outlet channel.

16 . The shotgun of claim 15 , wherein the one or more vents of the body of the fore-end portion are defined along an upper surface of the fore-end portion and are arranged to provide a generally downwardly directed force to at least partially reduce muzzle climb experienced during firing of the shotgun.

17 . The shotgun of claim 10 , wherein the fore-end portion is formed from wood, laminates, synthetics, composite materials, or combinations thereof.

18 . A kit for a firearm to facilitate firing rounds of different or varying shot loads, the kit comprising:

a series of exhaust tubes configured to be selectively interchanged or substituted to enable adjustment or tuning of the firearm for firing of specific cartridges or ranges of cartridges having different or varying shot loads;

each exhaust tube of the series of exhaust tubes comprising:

a body having a fluid passageway defined therethrough;

a rear portion having a first portion of the fluid passageway defined therein, and configured to be coupled to a gas block of the firearm such that the fluid passageway of the rear portion is in communication with a longitudinal piston bore of the gas block;

a front portion coupled to the rear portion and comprising a second portion or combination of fluid passageway in the fluid passageway of the rear portion, and an outlet to facilitate release of gases from the gas block generated from firing the firearm; and

a regulating portion disposed along an upstream end of the first portion of fluid passageway, that extends through the rear portion of the exhaust tube, the regulating portion configured to be used with selected cartridge loads or ranges thereof to enable replacement or change-out of the exhaust system components as needed to facilitate firing of cartridges having different loads.